Mold for making bell-mouthed concrete pipe.



PATENTED JULY 17, 1906. A. P. MELTON.

MOLD FOR MAKING BELL MOUTHBD APPLICATION FILED JULYIO,

CONCRETE PIPE.

III. I w llll UNITED STATES PATENT OFFIOE.

ARTHUR P. MELTON, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO MIRACLE PRESSEDSTONE COMPANY, OF SIOUX FALLS, DAKOTA, AND MINNEAPOLIS, MINNESOTA, ACORPORATION SOUTH DAKOTA.

SOUTH OF Specification of Letters Patent.

' Patented July 1'7, 1906.

Application filed July 10, 1905. Serial No, 268,967-

To all whom it may concern:

Be it known that I, ARTHUR P. MnLroN, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented new and useful Improvements in Molds for MakingBell-Mouthed Concrete Pipe, of which the following is a specification,reference being had to the accompanying drawings, forming a partthereof.

The purpose of this invention is to provide an improved mold structurefor molding concrete pipe which have a flaring or bell mouth, oneimportant purpose being to avoid the necessity of retaining upon thepipe during the curing process the more expensive mold parts, and soavoiding the necessity for providing a large number of these expensiveparts for an operating plant.

It consists, of the features of construction set out in the claims.

In the drawings, Figure 1 is a side elevation of a mold embodying thisinvention. Fig. 2 is a vertical axial section of such mold, showing thebell-mouth portion of the molded pipe therein. Fig. 3 is a verticalsection showing the molded pipe and the part of mold which is retainedin connection with the pipe during curing, all other parts beingremoved. Fig. 4 is a top plan view of the mold. Fig. 5 is an axialsection of the bellmouth parts of the mold and a deflector used infilling the bell-mouth cavity in the first step of-molding.

The present method of molding bellmouthed concrete pipe requires acollapsible inner member of the mold and an exp ansible outer member,which are supported with the bell-mouthed end upward for filling theannular interspace between them with the concrete and tamping it in toform the pipe. In its green or soft condition the straight cylindricalportion of the pipe will sustain its own weight without injury duringthe curing process; but the bell-mouth at the upper end if not supportedexteriorly tends to collapse or subside and become distorted by its ownweight before the concrete is sufliciently cured to carry that weight,overhanging, as it does, from the junction of the bell with the body.Therefore while the inner element of the mold may be withdrawn after themolding is completed the outer element is necessarily left in position,retaining the molded pipe until it is sufiiciently dry to carry theweight of the bell-mouth piece safely. The outer member of the mold isthe more expensive part, and the continuous manufacture of such pipesfor this method requires a large investment in these outer members ofthe mold, making anexpensive plant.

The present invention consists in a mold having the cylindrical or bodyportion of the inner member separable from the bell-mouth portion, andpreferably having also the outer element constructed with thecylindrical portion separable from the bell-mouth portion.

A represents the pipe formed in the mold.

B is the cylindrical or body element of the inner member of the mold.

O is the bell-mouth element of the inner member.

D is the cylindrical body element of the outer member. The bell-mouthelement of said outer member comprises two similar parts E E and meansfor securing them together hereinafter described. The bellmouth element0 of the inner member may be a single integral form exteriorly shapedaccording to the dimensions and configuration desired at the innersurface of the bellmouth, and for the ordinary form of such pipe it is asimple metal annulus, angle form in cross-section, with aslightly-rounded exterior corner, the outer or peripheral verticalflange of the angular annulus being slightly tapered, so as to draw fromthe concrete pipe as a pattern draws from the sand and as customary inmolding such articles. It is thereby adapted to be withdrawn bodily andin one piece from the bell-mouthed pipe after the latter is fully cured.The horizontal flange of this element is preferably rabbeted at theinner circumference, as seen at c, a bead or fillet 0 being thrown upbounding the rabbet, and in the rabbet the lower end of the cylindricalor body element B of the inner member of the mold is stepped andexpanded to fit the rabbet closely. For the purpose of thus expandingthis cylindrical element of the inner member any convenient constructionmay be employed. I have shown the means for that purpose, which aredescribed fully in Patent No. 778,907, granted to Levi Shell January 3,1905, comprising brackets 1 1, secured rigidly to the inner side of thecylindrical-l body,'element B, and mounted in these brackets llthef'vertical shaft 2, from whose ends links 3 3 extend to the innerlapped edge of the cylindrical shell to which the links are pivotallyconnected, and from the same pivots links 4 4 extend to the arms 5 5 ofa rock-shaft 6, which is journaled in the brackets near thecircumference of the cylinder, said rock-shaft being provided with thelever-arm 7 at the upper end for rocking the shaft. When the shaft isrocked to fold the joints at which the links 4 4 and the lever-arms 5 5are connected, the cylinder-shell is collapsed or reduced in diameter,and when the shaft is rocking to with the lever-arms it is expanded. Theouter lapped edge of the shell is chamfered off to avoid forming ashoulder on the inner face of the pipe. The two parts E E of thebell-mouth element of the outer member are each provided with lugs 9 9,projecting outwardly at their proximate ends, and threesided clamps ordouble hooks 1O 10 are provided, adapted to be driven over lugs whichare suitably recessed at their opposite outer faces to seat the clamps,a slight taper being given to these outer faces and corresponding taperto the bars of the clamps, so that in driving the clamps onto the lugsthe two parts E E are drawn tightly together at their junction edges,each part constituting onehalf of the bell-mouth and the junction beingat the diametric plane.

The cylindrical or body element D of the outer mold member is formed ofheavy sheet metal orplate with the edges lapped similarly to thecorresponding elements of the inner member, and any suitable means maybe employed for tightening or closing up this element adapted to relaxit for the slight expansion necessary to permit it to be withdrawnendwise from the molded body. I have shown as the means for contractingand expanding this element of the outer member of the mold the devicesshown in said Patent No. 778,907, consisting in a rock-shaft 15,journaled in suitable clips 16 upon the outer side of the cylindricalshell D, said rock-shaft being bent to form cranks 18 18 between theclips 16 and these cranks being connected by links 17 17 with the otheror inner lapped ply or edge of the shell, clips 19 19 being rivetedthereonto for connection of the links 17 therewith. A lever-handle 20 onthe rock-shaft 15 serves for rocking it to swing the crankwrists downupon the outer surface of the shell at the side remote from the clips 19for contracting the shell or up from said surface and over toward theclips 19 for expanding it to permit its Withdrawal.

It will be understood that any other suitable means for expanding andcontracting the shell may be employed.

The lower end of the shell D is adapted to bring the links in line.

be stepped upon the upper edge of the bellmouth elements E E the innersurface of the shell being flush with the inner edge of said bell-mouthas nearly as may be. For retaining it thus accurately stepped on thebellmouth element lugs 21 21 are bolted to the shell D near the loweredge and offset outwardly therefrom'and extended to project somewhatbelow the lower-end, and the bellmouth members E E are cut away orrabbeted at 22 22 to afiord engagement for the lugs which thus check theshell against lateral movement which would displace its lower end fromthe upper position, step ed, as described, on the upper end of theBellmouth element.

In the use of this mold the bell-mouth element B of the inner member islodged on any suitable supportingplate, as a board F, which may beprovided with three pins or studs F F F for locating and centering suchmember, and the two parts E E of the bellmouth element of the outermember are then lodged on the board and secured together by the clamps10 and centered by three studs F F F with which the board is providedfor that purpose. A cone-shaped hood G, whose mouth is fitted to theinner circumference of the inner bell-mouth element B, is lodged thereonin the rabbet c, in which the cylindrical body element 0 of the innermember is ultimately to he stepped, said hood being cylindrical at itslower margin for a short distance, so as to fit the rabbet and keep itclear to receive the said inner c lindrical element 0 at the properstage. W ile the hood is in place the concrete is tamped into theannular cavity between the two bell-mouth elements of the inner andouter mold members, respectively, and the bell portion of the pipe isthereby formed up to the top of the outer member and as far up as thecylindrical portion of the hood, preferably leaving the concrete surfacesloped downward from the outer to the inner circumference, as indicated7 by the dotted line 90 90 on Fig. 2. The hood G is then removed and thecylindrical or body element B of the inner mold member is put into lace,stepped, as described, on the bellmout element 0 of said inner member.The I I5 molding of the p'pe may be now continued by tamping in materialuntil it is level up to the top of the outer bell element. Thecylindrical or body element D of the outer member is now put in positionupon the to of the I 2 bell element E E, and the molding of t e pipe iscompleted by tamping material to fill the annular interspace between thetwo cylindrical elements. When this process is completed, the innercylindrical body element B 12 5 being contracted by the means describedmay be withdrawn endwise. The corresponding cylindrical body element Dof the outer member being expanded by the means described may be thensimilarly withdrawn. I3

The clamps being withdrawn, the two parts E E of the bell element of theouter member may be withdrawn, and the molded pipe may then be left tocure, standing on the supporting-board F with the bell-moutli element ofthe inner member supporting the bell of the pipe and upholding thecylindrical body element by extending under its lower end within thebell. By this means the only part of the mold which it is necessary toprovide in multiple in order to leave it with the molded pipe duringcuring is the smallest, simplest, and cheapest of all the partsnamely,the simple angular annulus I claim 1. A mold for a bell-mouthed concretepipe comprising an inner member consisting of a bell-mouth part at thebottom and a cylindrical body part stepped on the top of the bell-mouthpart and contractible while so stepped thereon and separable therefromby direct lifting, and an outer member also consisting of a bell-mouthpart at the bottom and a cylindrical body part stepped on the top of thebell-mouth part and expansible while so stepped and separable therefromby direct lifting.

2. A mold for a bell-mouthed concrete pipe comprising an inner memberconsisting of a bell-mouth part at the bottom interiorly rabbeted at itsupper end; a contractible cylindrical body part stepped in the rabbet atthe top of the bell-mouth part and adapted to be separated therefrom bydirect lifting,- and an outer member consisting of a bell-mouth part atthe bottom and an eXpansible cylindrical body part stepped on thebell-mouth bottom part and separable therefrom by direct lifting.

In testimony whereof I have hereunto set my hand, in the presence of twowitnesses, at Minneapolis, Minnesota, this 20th day of June, 1905. I

ARTHUR P. MELTON. Witnesses:

L. SOPHIA BREVIG, MABEL MoPHEE.

